Pulp-screen.



R. S. CLARKE.

PULP SCREEN.

APPLICATION FILED MAY 29. I916.

mm w Patented Jan. 2,1917.

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PULP SCREEN.

APPLICATION FILED MAY 29. I916.

1,21 @,905, Patented Jan. 2, 1917.

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PULP-SCREEN.

Specification of Letters ratent.

Patented Jan. 2, 191?.

Application filed Kay 29, 1916. Serial No. 100,687.

To all whom it may concern Be it known that I, RALPH S. OLARKE,-&citizen of the United States, residing at East Wal ole, in the county ofNorfolk and State of iassachusetts, have invented new and usefulImprovements in Pulp-Screens, of which the following is a specification,referenoe being had to the accompanying drawings forming part thereof.

This invention has reference to improvements in machines for screeningor straining fibrous material, usually delivered to the machine as pulp,and particularly to that class of such ulp screening machines havingrotary cylindrical pulp screens.

The invention relates more especially to mechanism for effecting theprogressive rotation of the pulp gathering cylinders or screens toprogressively carry the pulp gathered by said screens to positions to beacted upon by the water sprays, and to produce oscillatory action of thescreen during such rotation to facilitate the passage of parts of thepulp through the screen.

One object of the invention is to construct a pulp gathering cylinderand the means for effecting oscillation thereof that intermittentrotation of the screen is effected as one result of said oscillation.

Another object of the invention is to improve the construction of thescreen OSClllating mechanism.

Other objects of the invention will appear from the followingdescription.

The invention consists in the constructlon of the means for rotatablysustaining'the pulp gathering screen.

The invention also consists in such other novel features of constructionand combination of pms as shall hereinafter be more fully described andpointed out 1n the claims.

Figure 1, represents an end vlew of the improved pulp screening machine.F g. 2, represents a plan view of the-same. Fig. 3, represents anenlarged detail v1ew of one of the arms or members for sustaining thescreen.

Similar characters of reference designate corresponding partsthroughout.

As heretofore constructed pulp screening machines having cylindricalpulp gathering screens have been supplied with pivoted arms havingbearings to receive collars of the screens. Rapid vibration of said armshas been effected by cams and the reactive movements of said arms towardsaid cams has been resisted by buffers. In such machines additionalprovision has been made for rotatably driving the screens and more orless complication has resulted therefrom.

In carrying this invention into practice I construct a pulp screenhaving the usual pulp receiving tank or pan 5 mounted on end frames 6, 6which frames, in the present instance, have the members 7, 7 and 8, 8which extend beyond the sides of said tank 5. On the members 7, 7 aremounted the upwardly extending arms 9, 9 which curve inward toward thevertical center of the tank 5 and bearings 10, 10 the axes of.

which are substantially in horizontalalinement with the axis of the pulpgathering cylinder as will hereafter be pointed out. On the members 8, 8are mounted the frames or blocks 11, 11 carrying the lubricating devices12, 12 and having bearings in which is journaled the cam shaft 13furnished with the drive pulley 14 and with the cams 15, 15 to theperiphery of which lubricant is supplied from the devices 12, 12. Theseblocks 11, 11 have also the rods 16, 16 which are supplied with buffersor cushions 17, 17 of yielding construction or material against whichthe adjustable device constituted by the nuts 18, 18 bears.

In the bearings 10,10 of arms 9, 9 are journaled the pintles 19, 19 ofthe shaker arms 20, 20 which have curved ways 21, 21 having groups ofseats 22, 22 and 23, 23 spaced apart and extending transversely of saidways 21, 21 to receive the bearing blocks 24, 24 and 25, 25respectively. The forward or free ends of these arms 20, 20 have thetransverse members 26, 26 and the projections 27, 27 to receive theriders 28, 28 which are secured to the members 26, 26 bythe bolts 29,29. In these arms 20, 20 are vertical guide perforations through whichthe rods 16, 16 extend so that the cushioning devices 17 17 are locatedbetween said arms 20,

20 and the nuts 18, 18 of the respective rods 16, 16 and act yieldinglyagainst said arms 20, 20 to assist in overcoming the inertia of saidarms whereby said arms may react quickly from their upward movementscaused by the elevations of the cams 15, 15 acting against the riders28, 28.

The pulp gathering cylinder or screen 30 is of any usual constructionadapted to gather pulp on its periphery and to permit the passagethrough its wall of the -finer parts of said pulp. This cylinder orscreen 30 has at its ends the collars 31, 31 which are rotatablysustained by the bearing blocks 24, 24 and 25, 25, the diameters ofthese collars 31,31 being such that the axis of said collars isapproximately in alinement horizontally with the axis of the bearings10, 10 of arms 9, 9.

Pulpy material, usually small particles of fibrous matter and water, issupplied to the pan 5 in any well known manner and this supply of pulpis maintained during the operation of the machine. The depth of thispulp in the pan 5 is such that a large portion of the periphery of thecylinder 30 is in contact therewith and displaces a certain proportionof the pulp. As above indicated the purpose of cylinder 30 is to gatherpulpy material from the contents of said pan 5 and, in the rotation. ofsaid cylinder, to carry said gathered material beneath water spray fromthe pipe 33 which spray acts to wash usual interstices of the screen ofsaid cylinder, such passage of the particles of' pulp being assisted byeffecting the shaking or oscillation of the cylinder or screen.

By reference to Fi s. 1 and 3 of the drawings it will be seen that thegroups of hearing blocks 24, 24 and 25, 25 are so spaced apart on theways 21, 21 of the shaker arms 20, 20 as to constitute substantially twopoint bearings for the collars 31, 31 of the cylinder 30. While each ofsaid groups of blocks is shown as having ,their bearing blocks 24, 24 or25, 25, the number of said blocks in each group or bearing is notmaterial as the operation can be accomplished by one or more of saidblocks in each group, the feature of main importance being that thecollars 31, 31 are sustained at two points spaced apart and that saidcollars are free to rotate and oscillate relative to said bearin points.

ith a supply of pulp in pan 5 shaft 13 is driven at the desired speedand the cams 15, 15 act on their riders 28, 28 to effect the vibrationor oscillation of the free ends of arms 20, 20. As the free ends ofthese arms are suddenly thrown upward a similar motion is given to thecollars 31 31 of the screen or cylinder 30, action of the blocks thefiner particles of pulp through the 24, 24 against said collars 31, 31being somewhat greater than the action of the blocks 25, 2'5 thereonowing to the respective spacing of said grou s of blocks from the pivots19, 19 and their bearings. In effect the rapid upward impulses of theblocks 24, 24 against the collars 31, 31 tends to drive said collarsupward out of contact with said blocks 24, 24. At or about the upwardmovement of said arms 20, 20 the cushioning devices 17 17 begin to actto overcome the inertia ofsaidv arms 20, 20 while the mertia of thescreen or cylinder is overcome mainly by gravity so'that the free endsof arms 20, 20 react more quickly than the screen or cylinder 30. Also,it is to be understood, that the reactive (downward) movement of thescreen or cylinder 30 is resisted somewhat by the mass of pulp in thepan 5. The continued vibratory action of arms 20, 20 will thereforeeffect both the vibration of the screen or cylinder 30 and at the sametime an intermittent progressive relation thereof in the directionindicated by its arrow.

I prefer to make the blocks 24, 24 and 25, 25 of wood and to seat themas shown in the drawings so that said blocks, when they become worn, maybe driven from their seats and replaced by new blocks.

By the use of the novel mounting for the rider or striker members 28,28, these members can conveniently be renewed from time to tlme.

I find it desirable to supply oil or other lubricant to the cams 15, 15during the operation of the machine to maintain a good lubricationbetween said cams and their riders or strikers 28, 28.

Having thus described my invention I claim as new and desire to secureby Letters Patent.

1. A pulp screening machine comprising a frame, a pulp receiving ansustained by said frame, arms and bloc s on said frame arranged in pairsat the respective sides of said pan, a shaft journaled in said blocksand havlng cams, screen carrying members plvotally mounted on said armsand having screen supporting bearings spaced apart and elements bearingon said cams, a cylindrical pulp screen having-collars sustained by saidspaced bearings, said screen carrying members having perforationsadjacent their free ends, rods mounted on said blocks and extendingthrou h said perforations yieldmg reacting bu ers mounted on said rodsabove said members to resist the upward movement of said members and toexert reactive pressure thereon, and'means at the upper ends of saidrods to adjust the pressure of said bufi'ers.

2. A pulp screening machine comprising a frame having a pulp receivingpan and a mmeoa pair of arms extending upward at the ends of said pan, apair 0 horizontal members pivotally-sustained by said arms and ha attheir free ends horizontal abutments and vertical webs, riding devicesremovably secured against said abutments and webs, said members havingbearings to rotatablyreceive elements of a cylindrical screen,ta pair ofrotatable cams acting against said ri ing devices and 'elding meansactin to press 1 downward t e free ends of sai pivoted members.

RPH s. or.-

